1. Field of the Invention
The present invention relates to an image processing apparatus for selecting a representative image from a group of sequential images that are taken by an image taking apparatus such as a capsule endoscope and for displaying the representative image; an image processing method; and an image processing program.
2. Description of the Related Art
Capsule endoscopes are commonly used as means of taking in-vivo images. A capsule endoscope takes images of internal organs at 2 to 4 fps for about 8 hours from when it is swallowed by a subject who is a patient until it is naturally discharged. The images are taken while the capsule endoscope moves through the stomach, the small intestine, and the large intestine due to peristalsis in the alimentary canal. The number of in-vivo images that the capsule endoscope takes in one examination can be up to about 60,000.
As described in, for example, Japanese Patent Application Laid-open No. 2004-321603, in general, the in-vivo images that are taken by a capsule endoscope are reproduced and displayed chronologically as if reproducing a moving image and are observed. An image processing apparatus is known as well that selects a predetermined number of representative images from a group of sequential images and displays the representative images to represent the overall trend of the group of sequential images. For example, the image processing apparatus described in “A Machine Learning Framework Using SOMs: Application in the Intestinal Motility Assessment” uses SOM (Self Organized Maps) to select representative images from a group of sequential in-vivo images and to display the representative images.